Axiom Home Page Forums General Discussion Stereo Adding speakers to a simple 2 channel system

I guess the answer depends a bit on the receiver being used. You might get lucky and have a receiver which has pre-out and amp-in connections on the back (my HK-3270 does), in which case you could use a couple of Y splitter cables to connect each pre-out to both amp-in and the corresponding (right/left) input on the other amplifier.

Failing that, if you are only using an external audio source (eg CD player) then you could use splitter cables from the source going to both the receiver and the new amp.

In both cases you would need a gain/level control on the second amplifier to make sure your levels match... might need a wider range with the second approach.

Failing that I guess the remaining options (none of which are great) would be:

- add the third pair of speakers in parallel with one of the existing sets and hope the amp can handle it (basically you'll have three pairs of speakers in parallel, so <3 ohm effective impedence)

- wire two pairs of speakers in series on one of the outputs, giving you a series-parallel arrangement - impedance will be OK (~6 ohms) but the speakers wired in series will not play as loudly as the other set of speakers... this probably only works if different speaker volume could be useful, eg you may want more or less volume on the patio than inside

A final option (which could work OK but more fiddly) would be to build/find a box that converts speaker-level signal to line level, could be as simple as a dual 1K potentiometer with speaker red connected to one end, speaker ground connected to the other end, RCA jack ground connected to speaker ground, and RCA jack hot connected to the wiper on the potentiometer. Fixed resistors would be better but would require some trial & error unless the second amp had sufficiently wide range of input levels & gain control.

An adapter like this would have a sufficiently high input impedance that you could wire it in parallel with either speaker pair without a problem.

EDIT - actually those adapters seem to be pretty common, so maybe this isn't as much of a "last resort" as I first thought. Search for "speaker to line level converter".

EDIT AGAIN - another option *might* be the headphone jack, but that would probably need resistors to bring the level down as well.